Administration of the MapR-DB is done primarily via the command line (maprcli) or with the MapR Control System (MCS). Regardless of whether the MapR-DB table is used for binary files or JSON documents, the same types of commands are used with slightly different parameter options. MapR-DB administration is associated with tables, columns and column families, and table regions.

The MapR Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the MapR cluster. This section describes considerations when upgrading the service, how to modify configuration settings, and how to administer and manage the service.

Enabling and Configuring Replication Role Balancer

You can enable or disable replication role balancer and configure role balancer
using MCS and the CLI.

Enabling and Configuring Replication Role Balancer Using the MapR Control
System

Log in to MCS and click Admin > Cluster Settings > Balancer.

Use the Enabled slider to enable
(Yes) or disable (No) role
balancer and:

Proceed to step 3 if you enabled the role balancer.

Skip to step 4 if you disabled the role balancer.

Select one of the presets or specify a custom value for
Concurrent Role Rebalancer and Delay
for Active Data in Seconds settings. You can choose:

Presets:

Default

Concurrent Role Rebalancer —
20%

Delay for Active Data in
Seconds — 600 sec

Rapid

Concurrent Role Rebalancer —
5%

Delay for Active Data in
Seconds — 300 sec

Moderate

Concurrent Role Rebalancer —
10%

Delay for Active Data in
Seconds — 600 sec

Relaxed

Concurrent Role Rebalancer —
25%

Delay for Active Data in
Seconds — 1800 sec

Custom, use the slider to set the concurrent
role rebalancer percentage and delay for active data in
seconds.

Here:

Concurrent Role
Rebalancer

Specifies the maximum percentage of data affected by
concurrent role rebalancer operations. The cluster will wait
until the number of rebalancing operations affects less than
this percentage of total data eligible for
rebalancing.

Delay for Active Data in
Seconds

At the time of calculation, role rebalancer will skip
any data recently active within this time interval. This
prevents unnecessary tampering with data used in recent or
ongoing computations.

Click Save Changes for the changes to take effect.

Enabling and Configuring Replication Role Balancer Using the CLI

You can use the config
save command to modify the replication role balancer parameter values.